v 5.4 ezo-ec

Range 0.07 − 500,000+ µS/cm

+/– 2%Accuracy

1 reading per secResponse time

K 0.1 – K 10 any brandSupported probes

2 or 3 pointCalibration

UART & I2CData protocol

100 (0x64)Default I2C address

3.3V − 5VOperating voltage

ASCIIData format

YesTemp compensation

Reads Conductivity = µS/cmTotal dissolved solids = ppm

Salinity = PSUSpecific gravity

(sea water only) = 1.00 – 1.300

EZO-EC™Embedded Conductivity Circuit

V 5.4Revised 10/23/18

This is an evolving document, check back for updates.Written by Jordan PressDesigned by Noah Press

PATENT PROTECTED

This is sensitive electronic equipment. Get this device working in a solderless breadboard first. Once this device has been soldered it is no longer covered by our warranty.

This device has been designed to be soldered and can be soldered at any time. Once that decision has been made, Atlas Scientific no longer assumes responsibility for the device’s continued operation. The embedded systems engineer is now the responsible party.

Get this device working in asolderless breadboard first!

Do not embed this device withouttesting it in a solderless breadboard!

1 5 10 15 20 25 30

1 5 10 15 20 25 30

ABCDE

FGHIJ

ABCDE

FGHIJ

r 0.1

UART I2C

Circuit dimensionsPower consumptionAbsolute max ratingsEZO TM circuit identificationConductivity probe range Resolution

Operating principleOutput unitsCalibration theoryPower and data isolationCorrect wiringAvailable data protocols

Circuit footprintDatasheet change logWarranty

UART modeDefault stateReceiving data from deviceSending commands to deviceLED color definitionUART quick command pageLED controlFindContinuous reading modeSingle reading modeCalibrationExport/import calibrationSetting the probe typeTemperature compensationEnable/disable parametersNaming deviceDevice informationResponse codesReading device statusSleep mode/low powerChange baud rateProtocol lockFactory resetChange to I2C modeManual switching to I2C

I2C modeSending commandsRequesting dataResponse codesLED color definitionI2C quick command pageLED controlFindTaking readingCalibrationExport/import calibrationSetting the probe typeTemperature compensationEnable/disable parametersDevice informationReading device statusSleep mode/low powerProtocol lockI2C address changeFactory resetChange to UART modeManual switching to UART

444567

17181920212223242526272829303132333435363738394041

8910121415

656669

43444546474849505152535455565758596061626364

Table of contents

3 Copyright © Atlas Scientific LLC

Power consumption

0.7 mA

0.4 mA

LED MAX STANDBY SLEEP

ON 50 mA 18.14 mA

45 mA 15.64 mA

35 mA 16.85 mA

34 mA 15.85 mA

ON

OFF

OFF

5V

3.3V

Absolute max ratingsMIN MAXTYPParameter

-60 °C 150 °C

125 °C25 °C-40 °C

Storage temperature(EZO™ Conductivity)

VCC

Operational temperature(EZO™ Conductivity)

5V 5.5V3.3V

EZO TM circuit dimensions 13.97mm(0.55”)

20.16mm(0.79”)

8.38mm(0.32”)

10.8mm(0.4”)

5.8mm(0.22”) 1mm Ø

r 0.1


EZO TM circuit identification

Viewing correct datasheet Viewing incorrect datasheet

EZO™ Conductivity circuit Legacy Conductivity circuit

Click here to view legacy datasheet

r 0.1

3.03.0


https://www.atlas-scientific.com/_files/_datasheets/_circuit/EC_Circuit_3.0.pdf

Conductivity probe rangeThe EZO™ Conductivity circuit is capable of connecting to any two-conductor conductivity probe, ranging from:

Atlas Scientific™ does not know what the accurate reading range would be for conductivity probes, other than the above mentioned values. Determining the accurate reading range of such probes, i.e. K 2.6, or K 0.66, is the responsibility of the embedded systems engineer.

Atlas Scientific™ has tested 3 different K value probe types

accurate reading range accurate reading range accurate reading range

0.07µS – 50,000µS 5µS – 200,000+µS 10µS – 1S

K 1.0 K 10K 0.1


ResolutionThe EZO™ Conductivity circuit, employs a method of scaling resolution. As the conductivity increases the resolution between readings decreases.

The EZO™ Conductivity circuit will output conductivity readings where the first 4 digits are valid and the others are set to 0. This excludes conductivity readings that are less than 9.99. In that case, only 3 conductivity digits will be output.

0.07 – 99.99Resolution = 0.01µS

100.1 – 999.9Resolution = 0.1µS

1,000 – 9,999Resolution = 1.0µS

10,000 – 99,990Resolution = 10µS

100,000 – 999,900Resolution = 100µS

13.97mm(0.55”)

20.16mm(0.79”)

8.38mm(0.32”)

10.8mm(0.4”)

5.8mm(0.22”) 1mm Ø


Operating principleAn E.C. (electrical conductivity) probe measures the electrical conductivity in a solution. It is commonly used in hydroponics, aquaculture and freshwater systems to monitor the amount of nutrients, salts or impurities in the water.

Inside the conductivity probe, two electrodes are positioned opposite from each other, an AC voltage is applied to the electrodes causing cations to move to the negatively charged electrode, while the anions move to the positively electrode. The more free electrolyte the liquid contains, the higher the electrical conductivity.

AC voltage

Epoxy body

Graphite

Epoxy body

Graphite

Epoxy body

Glass stem

Platinum

Platinum

AC voltage

Epoxy body

Graphite

Epoxy body

Graphite

Epoxy body

Glass stem

Platinum

Platinum

K 0.1Graphite electrode

K 1.0 K 10Graphite electrode Platinum electrode


Output units

The EZO™ Conductivity circuit also has the capability to read:

Conductivity = µS/cmTotal dissolved solids = ppmSalinity = PSUSpacific gravity (sea water only) = 1.00 – 1.300

These parameters must be individually enabled within the device. See page 31 to enable each parameter in UART mode, and on page 56 for I2C mode.

Once these parameters have been enabled, output will be a CSV string.

ExampleEC,TDS,SAL,SG

By default, EZO™ Conductivity circuits with firmware version 2.10 and above will only output EC. To enable these parameters see page 31 for UART, and 56 for I2C.

1,000 ms

GreenStandby

CyanTaking reading Transmitting

Correct

This is the LED pattern for Continous Mode (default state)This can only happen when the device is in UART mode.

Default LED blink pattern


Calibration theory

First, take readings from dry conductivity probe.

Pre-calibration setup

Set probe type

Dry calibration

If you are not using a K 1.0 conductivity probe (default), you need to set the probe type by using the "K,n" command. (where n = K value of your probe)

0.00

0.00

17.00

00.00

1 5 10 15 20 25 30

1 5 10 15 20 25 30

ABCDE

FGHIJ

ABCDE

FGHIJ

1 5 10 15 20 25 30

1 5 10 15 20 25 30

ABCDE

FGHIJ

ABCDE

FGHIJ

1,413µS

TM

“Cal,dry”

25°C / 77°F+/- 5

1,413µS

°C

5 41 896

10 50 1,020

15 59 1,147

20 68 1,278

25 77 1,413

°F °C

30 86 1,548

35 95 1,711

40 104 1,860

45 113 2,009

50 122 2,158

°F

ConductivitySolution

KCl125ml

Atlas-Scientific.com/msds.html

TM

µS/cm µS/cm

8 5 7 4 3 4 0 0 5 0 3 9

1 5 10 15 20 25 30

1 5 10 15 20 25 30

ABCDE

FGHIJ

ABCDE

FGHIJ

1 5 10 15 20 25 30

1 5 10 15 20 25 30

ABCDE

FGHIJ

ABCDE

FGHIJ

1,413µS

TM

“Cal,dry”

25°C / 77°F+/- 5

1,413µS

°C

5 41 896

10 50 1,020

15 59 1,147

20 68 1,278

25 77 1,413

°F °C

30 86 1,548

35 95 1,711

40 104 1,860

45 113 2,009

50 122 2,158

°F


KCl125ml


TM

µS/cm µS/cm

8 5 7 4 3 4 0 0 5 0 3 9

1 5 10 15 20 25 30

1 5 10 15 20 25 30

ABCDE

FGHIJ

ABCDE

FGHIJ

1 5 10 15 20 25 30

1 5 10 15 20 25 30

ABCDE

FGHIJ

ABCDE

FGHIJ

1,413µS

TM

“Cal,dry”

25°C / 77°F+/- 5

1,413µS

°C

5 41 896

10 50 1,020

15 59 1,147

20 68 1,278

25 77 1,413

°F °C

30 86 1,548

35 95 1,711

40 104 1,860

45 113 2,009

50 122 2,158

°F


KCl125ml


TM

µS/cm µS/cm

8 5 7 4 3 4 0 0 5 0 3 9

1,000 ms

GreenStandby


Correct

1,000 ms

GreenStandby


Correct

The most important part of calibration is watching the readings during the calibration process. It's easiest to calibrate the device in its default state (UART mode, continuous readings). Switching the device to I2C mode after calibration will not affect the stored calibration. If the device must be calibrated in I2C mode be sure to request readings continuously so you can see the output from the probe.

Issuing the "Cal,dry" command fine tunes the internal electrical properties of the device. This calibration only needs to be done once. Even though you may see reading of 0.00 before issuing the "Cal,dry" command, it is still a necessary component of calibration.


1 5 10 15 20 25 30

1 5 10 15 20 25 30

ABCDE

FGHIJ

ABCDE

FGHIJ

1 5 10 15 20 25 30

1 5 10 15 20 25 30

ABCDE

FGHIJ

ABCDE

FGHIJ

1,413µS

TM

“Cal,dry”

25°C / 77°F+/- 5

1,413µS

°C

5 41 896

10 50 1,020

15 59 1,147

20 68 1,278

25 77 1,413

°F °C

30 86 1,548

35 95 1,711

40 104 1,860

45 113 2,009

50 122 2,158

°F


KCl125ml


TM

µS/cm µS/cm

8 5 7 4 3 4 0 0 5 0 3 9

Low point/single point calibrationPour a small amount of the calibration solution into a cup. Shake the probe to make sure you do not have trapped air bubbles in the sensing area. You should see readings that are off by 1 – 40% from the stated value of the calibration solution. Wait for readings to stabilize (small movement from one reading to the next is normal).

Once the readings stabilize, issue the low point or single point calibration command.Low point calibration: "Cal,low,1413" (Readings will NOT change)Single point calibration: "Cal,1413" (Readings will change, calibration complete).

check probe connection,you cannot calibrate to 0.

1 5 10 15 20 25 30

1 5 10 15 20 25 30

ABCDE

FGHIJ

ABCDE

FGHIJ

1 5 10 15 20 25 30

1 5 10 15 20 25 30

ABCDE

FGHIJ

ABCDE

FGHIJ

1,413µS

TM

“Cal,dry”

25°C / 77°F+/- 5

1,413µS

°C

5 41 896

10 50 1,020

15 59 1,147

20 68 1,278

25 77 1,413

°F °C

30 86 1,548

35 95 1,711

40 104 1,860

45 113 2,009

50 122 2,158

°F


KCl125ml


TM

µS/cm µS/cm

8 5 7 4 3 4 0 0 5 0 3 9

1,413µS

847.8μS – 1978.2μS

1,413µS

0.00μS

1,413µS

847.8μS – 1978.2μS

1,413µS

0.00μS

Trapped air(shake to remove)

1,413µS1,413µS

Temperature has a significant effect on conductivity readings. The EZO™ Conductivity circuit has its temperature compensation set to 25˚ C as the default. If the calibration solution is not within 5˚ of 25˚ C, check the temperature chart on the side of the calibration bottle, and calibrate to that value.

Temperature compensation

High point calibrationShake the probe to remove trapped air and adjust the temperature as done in the previous step. Once the readings have stabilized issue the high point calibration command.High point calibration: "Cal,high,12880" (Readings will change, calibration complete).


1 5 10 15 20 25 30

1 5 10 15 20 25 30

ABCDE

FGHIJ

ABCDE

FGHIJ

1 5 10 15 20 25 30

1 5 10 15 20 25 30

ABCDE

FGHIJ

ABCDE

FGHIJ

Correct1 5 10 15 20 25 30

1 5 10 15 20 25 30

ABCDE

FGHIJ

ABCDE

FGHIJ

1 5 10 15 20 25 30

1 5 10 15 20 25 30

ABCDE

FGHIJ

ABCDE

FGHIJ

Incorrect

Power and data isolationThe Atlas Scientific EZO™ Conductivity circuit is a very sensitive device. This sensitivity is what gives the Conductivity circuit its accuracy. This also means that the Conductivity circuit is capable of reading micro-voltages that are bleeding into the water from unnatural sources such as pumps, solenoid valves or other probes/sensors.

When electrical noise is interfering with the Conductivity readings it is common to see rapidly fluctuating readings or readings that are consistently off. To verify that electrical noise is causing inaccurate readings, place the Conductivity probe in a cup of water by itself. The readings should stabilize quickly, confirming that electrical noise was the issue.

When reading from two EZO™ Conductivity circuits, it is strongly recommended that they are electrically isolated from each other.

Without isolation, Conductivity readingswill effect each other.

1 5 10 15 20 25 30

1 5 10 15 20 25 30

ABCDE

FGHIJ

ABCDE

FGHIJ

1 5 10 15 20 25 30

1 5 10 15 20 25 30

ABCDE

FGHIJ

ABCDE

FGHIJ

Correct1 5 10 15 20 25 30

1 5 10 15 20 25 30

ABCDE

FGHIJ

ABCDE

FGHIJ

1 5 10 15 20 25 30

1 5 10 15 20 25 30

ABCDE

FGHIJ

ABCDE

FGHIJ

IncorrectBasic EZO TM

Inline Voltage Isolator

r 0.1


https://www.atlas-scientific.com/product_pages/circuits/basic-ezo.html

https://www.atlas-scientific.com/product_pages/circuits/basic-ezo.html

r 0.1

This schematic shows exactly how we isolate data and power using the ADM3260 and a few passive components. The ADM3260 can output isolated power up to 150 mW and incorporates two bidirectional data channels.

This technology works by using tiny transformers to induce the voltage across an air gap. PCB layout requires special attention for EMI/EMC and RF Control, having proper ground planes and keeping the capacitors as close to the chip as possible are crucial for proper performance. The two data channels have a 4.7kΩ pull up resistor on both the isolated and non-isolated lines (R1, R2, R3, and R4) The output voltage is set using a voltage divider (R5, R6, and R,7) this produces a voltage of 3.9V regardless of your input voltage.

Isolated ground is different from non-isolated ground, these two lines should not be connected together.

C4

10uF

C1

0.1uf

VDDP

ADM3260

HDR_BTM

ISO-VCC

ISO-VCC

ISO-VCC

ISO-VCC

ISO-VCC

R5 R7

R4

R3

1.5K

R6

1.5K

C3

C2

C6

C5

10uF

10uF

0.1uF

0.1uF

1.5K

4.7K

4.7K

VDDISOVISOVSEL

NCNC

SCL1SDA1

SCL2

SDA2

VIN

GNDPGNDISOGNDISOGNDISOGNDISO

GNDPGNDPGNDPPDIS

VCC

VCC

VCC

VCC

VCC

VCC

RX/SCLTX/SDA

NCGND

ISO-GND

ISO-GND

GND

R2 R14.7K 4.7K

R5

1M

HDR_TOPVCC

RX/SCLTX/SDA

ENGND

Non-isolated

N-FET

VCC = 3.0v − 5.5v

Isolated

D

G

S

GND

VCC

R8

1M


http://www.analog.com/en/products/interface-isolation/isolation/isolated-i2c-isolators/adm3260.html#product-overview

Correct wiring

Incorrect wiring

Bread board

Extended leads Sloppy setup Perfboards or Protoboards *Embedded into your device

Bread boardvia USB

USB carrier board

Part #USB-ISO

Part #ISCCB

Part # COM-104

Carrier board

1 5 10 15 20

1 5 15 15 20

ABCDE

FGHIJ

ABCDE

FGHIJ

1 5 10 15 20

1 5 15 15 20

ABCDE

FGHIJ

ABCDE

FGHIJ

TM

AtlasScientific

PWR

RX

TX

*Only after you are familarwith EZO TM circuits operation

11

55

1010

1515

2020

2525

3030

3535

4040

4545

5050

5555

6060

A

A

B

B

C

C

D

D

E

E

F

F

G

G

H

H

I

I

J

J

RX

TXGN

D

VC

C

use Perfboards or Protoboards

NEVER

r 0.1


SPI

Analog

RS-485

Mod Bus

4–20mA

Available data protocols

Unavailable data protocols

Default

r 0.1


UART mode

Settings that are retained if power is cut

Baud rateCalibrationContinuous modeDevice nameEnable/disable parametersEnable/disable response codesHardware switch to I2C modeLED controlProtocol lockSoftware switch to I2C mode

FindSleep modeTemperature compensation

Settings that are NOT retained if power is cut

r 0.2

UART mode

Data format

Vcc

RXData in

Data outTX

3.3V – 5.5V

Baud

8 data bits1 stop bit

no parityno flow control

3001,2002,4009,60019,20038,40057,600115,200

default

0V0V

VCC

CPU

TX RX

RX TX

TX RX

GreenUART standby

CyanTaking reading

PurpleChangingbaud rate

WhiteFind

RedCommand

not understood

Terminator carriage returnData type floating pointDecimal places 3Smallest string 3 charactersLargest string 40 characters

Reading

Units EC,TDS,SAL,SGEncoding ASCIIFormat string

Conductivity = µS/cmTotal dissolved solids = ppmSalinity = PSUSpecific gravity (sea water only) = 1.00 – 1.300


Default stateMode UART

9,600Baud

1,000 ms

GreenStandby


continuous

1 reading per second

on

Readings

Speed

LED

µS/cmUnits


Receiving data from device2 parts

Terminator

Carriage return <cr>

Hex:

Dec:

ASCII:

31

49

1 4

34

52

0D

13

CPU

TX RX

BlueI2C standby

GreenTaking reading

PurpleChanging

I2C ID#

WhiteFind

RedCommand

not understood

1,413 <cr>

9,600 baud(default)

Receiver

Advanced

ASCII data stringCommand

Sender

<cr>

r 0.1

,

2C

44

1 3

31 33

49 51


2 parts

Terminator

Carriage return <cr>

Sending commands to device

CPU

TX RX

Short

Short

Sender

Sleep <cr>

Command (not case sensitive)ASCII data string

Receiver

Hex:

Dec:

ASCII:

53

83

S l e e p

6C

108 101 101 112

65 65 70 0D

13

Advanced<cr>

r 0.1


CPU

TX RX

RX TX

TX RX

GreenUART standby

CyanTaking reading


WhiteFind

RedCommand

not understood

LED color definition

r 0.1

LED ON

5V

3.3V

+2.5 mA

+1 mA


command quick referenceUART mode

Command Default stateFunction

All commands are ASCII strings or single ASCII characters.

change baud rate 9,600Baud pg. 37

enable/disable continuous reading enabledC pg. 25

performs calibration n/aCal pg. 27

finds device with blinking white LED n/aFind pg. 24

device information n/ai pg. 33

change to I2C mode not setI2C pg. 40

Set probe type K 1.0K pg. 29

enable/disable LED enabledL pg. 23

enable/disable parameters all enabledO pg. 31

set/show name of device not setName pg. 32

enable/disable protocol lock disabledPlock pg. 38

returns a single reading n/aR pg. 26

enter sleep mode/low power n/aSleep pg. 36

retrieve status information enableStatus pg. 35

enable/disable response codes enable*OK pg. 34

temperature compensation 25˚CT pg. 30

export/import calibration n/aExport/import pg. 28

enable factory reset n/aFactory pg. 39


LED control

1,000 ms

GreenStandby


1,000 ms

GreenStandby


L,1 <cr>

<cr>

<cr>

LED on

L,0 LED off

L,? LED state on/off?

Command syntax

default

<cr>

<cr>

<cr>

<cr>*OK

<cr>*OKL,1

L,1 L,0

L,0

L,?

Example Response

<cr>

<cr>

<cr>?L,1 or ?L,0*OK

r 0.1



Baud rateCalibrationContinuous modeDevice nameEnable/disable parametersEnable/disable response codesHardware switch to I2C modeLED controlProtocol lockSoftware switch to I2C mode



Find

Find <cr> LED rapidly blinks white, used to help find device

Command syntax

<cr> <cr>*OKFind

Example Response

r 0.2

This command will disable continuous modeSend any character or command to terminate find.


r 0.2

Continuous reading mode

C,1 <cr>

<cr>

<cr>

<cr>

<cr>

<cr> <cr>*OK

enable continuous readings once per second

C,0 disable continuous readings

C,? continuous reading mode on/off?

default

Command syntax

C,1

C,30

C,0

*OKEC,TDS,SAL,SG (1 sec) EC,TDS,SAL,SG (2 sec)EC,TDS,SAL,SG (3 sec)

*OKEC,TDS,SAL,SG (30 sec) EC,TDS,SAL,SG (60 sec)EC,TDS,SAL,SG (90 sec)

<cr>

<cr>

<cr>

<cr>

<cr>

<cr>

<cr>

<cr>

Example Response

<cr>

<cr>?C,1 or ?C,0 or ?C,30*OK

<cr>C,?

<cr>C,n continuous readings every n seconds (n = 2 to 99 sec)

<cr> <cr>


Single reading mode

1,000 ms

GreenStandby


R <cr>

<cr>

takes single reading

Command syntax

R 1,413 *OK

<cr>

<cr>

Example Response

600 ms

r 0.1


Calibration

Dry calibration must always be done first!Command syntax

<cr>

<cr>

<cr>

<cr>*OK

<cr>*OK

<cr>*OK

<cr>*OK

<cr>*OK

Cal,dry

Cal,84

Cal,low,12880

<cr>

<cr>

Cal,high,80000

Cal,clear

Example Response

<cr>Cal,? ?CAL,0 or ?CAL,1 or ?CAL,2

*OK

<cr>

<cr>

<cr>three pointtwo point

<cr>

<cr>

<cr>

<cr>

<cr>

<cr>

Cal,dryCal,n

Cal,low,n

Cal,high,n

Cal,clear

Cal,?

dry calibrationsingle point calibration, where n = any value

low end calibration, where n = any value

high end calibration, where n = any value

delete calibration data

device calibrated?

Two point calibration:Step 1. "cal,dry"Step 2. "cal,n"Calibration complete!

Three point calibration:Step 1 "cal,dry"Step 2 "cal,low,n"Step 3 "cal,high.n"Calibration complete!


Export/import calibration

Export <cr>

<cr>

<cr>

export calibration string from calibrated device

Import import calibration string to new device

Export,? calibration string info

Command syntax

<cr> <cr>

<cr>

<cr>

<cr>

59 6F 75 20 61 72 (1 of 10)

(1 of 10)

(2 of 10)

(8 more)

(10 of 10)

(FIFO)

65 20 61 20 63 6F

6F 6C 20 67 75 79

*DONE

<cr>Import, 59 6F 75 20 61 72

<cr>Export

<cr>Export

<cr>Export

<cr>Export

10,120

Disabling *OK simplifies this process

Export,?

Example Response

Export: Use this command to save calibration settingsImport: Use this command to load calibration settings to one or more devices.

Import, n

Response breakdown

# of strings to export

Export strings can be up to 12 characters long,and is always followed by <cr>

10,# of bytes to export

120

r 0.1


Setting the probe type

K,n <cr>

<cr>

n = any value; floating point in ASCII

K,? probe K value?

Command syntax

<cr>

<cr>

<cr>*OKK,10

K,?

Example Response

?K,10*OK

<cr>

<cr>

K 1.0 is the default value

K 0.1 K 1.0 K 10



T,n <cr>

<cr>

<cr>

n = any value; floating point or int

T,?

RT,n

compensated temperature value?

set temperature compensation and take a reading*

Command syntax

SDA(TX) (RX)

SCL SDA(TX) (RX)

SCLSDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

<cr>

<cr>

<cr>

<cr>*OK

<cr>*OK<cr>8.91

T,19.5

RT,19.5

T,?

Example Response

?T,19.5 *OK

<cr>

<cr>

8.82

T,19.5 <cr>

8.91

This is a new commandfor firmware V2.13

r 0.2

Default temperature = 25°CTemperature is always in Celsius Temperature is not retained if power is cut


O, [parameter],[1,0] <cr>

<cr>

enable or disable output parameter

O,? enabled parameter?

Command syntax

enable / disable total dissolved solids

if all are enabled

<cr>

<cr>

<cr>

<cr>

enable / disable conductivity*OK <cr>

*OK <cr>

enable / disable salinity*OK <cr>

enable / disable specific gravity*OK <cr>

O,EC,1

O,SG,1 O,SG,0

<cr>O,EC,0/

/

/

/

O,TDS,1

O,S,1

O,TDS,0

O,S,0

Example Response

O,? ?,O,EC,TDS,S,SG <cr>

* If you disable all possible data types your readings will display “no output”.

ParametersEC conductivity

total dissolved solidssalinityspecific gravity

enableddisabled

TDSSSG

Followed by 1 or 010

Enable/disable parameters from output string


Naming device

Name,n <cr>

<cr>

set name

Name,? show name

Command syntax

<cr>

<cr>

<cr>*OKName,zzt

Name,?

Example Response

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _1 62 73 84 95 10 11 12 13 14 15 16

n =

Up to 16 ASCII characters

?Name,zzt*OK

<cr>

<cr>

*OK*OK <cr>

<cr>

Name,?Name,zzt

1,000 ms

GreenStandby


1,000 ms

GreenStandby


Name,zzt <cr>

r 0.1r 0.1


Device information

Response breakdown?i,

Device

EC,Firmware

2.10

i <cr>

<cr>

device information

Command syntax

i

Example Response

?i,EC,2.10*OK

<cr>

<cr>

r 0.1


Response codes

no response, *OK disabled

*OK disabled

Other response codes*ER unknown command

over volt (VCC>=5.5V)These response codescannot be disabled

under volt (VCC<=3.1V)resetboot up complete, readyentering sleep modewake up

*OV*UV*RS*RE*SL*WA

1,413*OK

1,413

*OK,1 <cr>

<cr>

<cr>

enable response

*OK,0 disable response

*OK,? response on/off?

Command syntax

<cr>

<cr>

<cr>

<cr>

<cr>

<cr>

R

R

*OK,0

Example Response

default

<cr>*OK,? ?*OK,1 or ?*OK,0<cr> <cr>

r 0.1


Reading device status

Restart codesP powered off

software resetbrown outwatchdog unknown

SBWU

?Status,Reason for restart

P,Voltage at Vcc

5.038

Response breakdown

Status <cr>

Command syntax

Example Response

?Status,P,5.038*OK

<cr>

<cr>

voltage at Vcc pin and reason for last restart

Status <cr>

r 0.1


Sleep mode/low powerSend any character or command to awaken device.

1,000 ms

GreenStandby


1,000 ms

GreenStandby


Sleep <cr>

Sleep <cr>

Command syntax

Example Response

*SL

*WA wakes up device

enter sleep mode/low power

Sleep

Any command

<cr>

<cr>

Sleep0.7 mA

Standby18.14 mA

r 0.1

STANDBY SLEEP

18.14 mA 0.7 mA

0.4 mA16.85 mA

5V

3.3V


1,000 ms

GreenStandby


Change baud rate

Baud,38400 <cr>

Changingbaud rate

Standby

1,000 ms

GreenStandby


Standby

CPU

TX RX

RX TX

TX RX

GreenUART standby

CyanTaking reading


WhiteFind

RedCommand

not understood*OK <cr>

(reboot)

Baud,n <cr>

Command syntax

change baud rate

n =

Example Response

*OKBaud,38400

Baud,?

<cr>

<cr>

<cr>

?Baud,38400*OK <cr>

<cr>

default

300120024009600192003840057600115200

r 0.1


Protocol lock

Plock,1 I2C,100

CPU

TX RX

RX TX

TX RX

GreenUART standby

CyanTaking reading


WhiteFind

RedCommand

not understood

CPU

TX RX

RX TX

TX RX

GreenUART standby

CyanTaking reading


WhiteFind

RedCommand

not understood

*OK <cr>*ER <cr>

CPU

TX RX

Short

Short

cannot change to I2C

*OK

*OK

?Plock,1 ?Plock,0or

Plock,1 <cr>

<cr>

<cr>

enable Plock

Plock,0 disable Plock

Plock,? Plock on/off?

Command syntax

<cr>

<cr>

<cr>

<cr>

<cr>

<cr> <cr>

Plock,1

Plock,0

Plock,?

Example Response

Locks device to UART mode.

cannot change to I2C

r 0.1

default


Factory resetClears calibration LED on"*OK" enabled

1,000 ms

GreenStandby


Factory <cr>

*RS <cr>*OK <cr>*RE <cr>

1,000 ms

GreenStandby


(reboot)

Factory <cr>

Command syntax

Example Response

*OK

enable factory reset

Factory <cr> <cr>

Baud rate will not change

r 0.1


Change to I2C mode

I2C,100

CPU

TX RX

RX TX

TX RX

GreenUART standby

CyanTaking reading


WhiteFind

RedCommand

not understood

CPU

TX RX

RX TX

TX RX

GreenUART standby

CyanTaking reading


WhiteFind

RedCommand

not understood

*OK <cr> now in I2C modeGreen Blue

I2C,n <cr>

Command syntax

Example

Wrong example

Response

Response

*OK (reboot in I2C mode)

*ERn > 127

sets I2C address and reboots into I2C mode

I2C,100

I2C,139

<cr>

<cr> <cr>

n = any number 1 – 127

(reboot)

r 0.2

Default I2C address 100 (0x64)


Manual switching to I2CMake sure Plock is set to 0 Disconnect ground (power off)Disconnect TX and RXConnect TX to the right PRBConfirm RX is disconnectedConnect ground (power on)Wait for LED to change from Green to BlueDisconnect ground (power off)Reconnect all data and power

•••••••••

CPU

TX RX

Short

Short

Wrong Example

Example

Disconnect RX line

Manually switching to I2C will set the I2C address to 100 (0x64)

r 0.1


r 0.2

I2C modeThe I2C protocol is considerably more complex than the UART (RS–232) protocol. Atlas Scientific assumes the embedded systems engineer understands this protocol.

To set your EZOTM device into I2C mode click here


CalibrationChange I2C addressEnable/disable parametersHardware switch to UART modeLED controlProtocol lockSoftware switch to UART mode



r 0.2

I2C mode

Vcc 3.3V – 5.5V

Clock speed 100 – 400 kHz

0V0V

VCC

I2C address (0x01 – 0x7F)

100 (0x64) default

SDA

SCL

SDA

4.7k resistormay be needed

0V0V

VCC

CPU

SCL SDA

SCL

SDA

VCC

SDA

SCL

CPU

SCL SDA

SDA(TX) (RX)

SCLSDA(TX) (RX)

SCL

SDA(TX) (RX)

SCL

VCC

SCL

Data formatFormat stringData type floating pointDecimal places 3Smallest string 3 charactersLargest string 399 characters

Reading

Units EC,TDS,SAL,SGEncoding ASCII

Conductivity = µS/cmTotal dissolved solids = ppmSalinity = PSUSpecific gravity (sea water only) = 1.00 – 1.300


5 parts

ASCII command string

Command (not case sensitive)Start100 (0x64)

I2C address Write

Write

Stop

StartI2C address100 (0x64) Stop

Command

Sleep

Sending commands to device

A6SDA

Start Stop

SCLA5 A4 A3 A2 A1 A0 W ACK ACK ACKFirst letter of command Last letter of command

The entire command as ASCII with all argumentsAddress bits

W = low

SCL

SDA

4.7k resistormay be needed

0V0V

VCC

CPU

SCL SDA

SCL

SDA

VCC

SDA

SCL

CPU

SCL SDA

SDA(TX) (RX)

SCLSDA(TX) (RX)

SCL

SDA(TX) (RX)

SCL

VCC

Advanced

Example

r 0.1


Terminator(Dec 0)

7 parts

1 byte "1,413"100 (0x64)

Response codeRead Data stringStart I2C address StopNull

A6 − A0SDA

SCLR ACK ACK ACK

N bytes of dataAll bytes

after data are NullAddress bits

ACKACK

NACK

Response code Data Data N NullNull

Start Stop

R = High

Requesting data from device

= 1,4131 0ASCII

Dec Dec

Advanced

CPU

SCL SDA

CPU

SDA(TX) (RX)

SCL

SDA(TX) (RX)

SCL

1,413

r 0.1

49 44 52 49 51


Response codes

I2C_start;I2C_address;I2C_write(EZO_command);I2C_stop;

delay(300);

I2C_start;I2C_address;Char[ ] = I2C_read;I2C_stop;

Processing delay

After a command has been issued, a 1 byte response code can be read in order to confirm that the command was processed successfully.

Reading back the response code is completely optional, and is not required for normal operation.

Example The response code will always be 254, if you do not wait for the processing delay.

Response codesSingle byte, not string

no data to sendstill processing, not readysyntax errorsuccessful request

25525421

CPU

SCL SDA

CPU

SDA(TX) (RX)

SCL

SDA(TX) (RX)

SCL

Receivingdata

Sendcommand

Processing delay

r 0.2


CPU

TX RX

BlueI2C standby

GreenTaking reading

PurpleChanging

I2C ID#

WhiteFind

RedCommand

not understood

LED color definition

r 0.1

LED ON

5V

3.3V

+2.5 mA

+1 mA


command quick referenceI2C mode

Command Function

All commands are ASCII strings or single ASCII characters.

performs calibrationCal pg. 52

switch back to UART modeBaud pg. 63

enable factory resetFactory pg. 62

device informationi pg. 57

change I2C addressI2C pg. 61

enable/disable LEDL pg. 49

enable/disable protocol lockPlock pg. 60

returns a single readingR pg. 51

enter sleep mode/low powerSleep pg. 59

retrieve status informationStatus pg. 58

temperature compensationT pg. 55

Set probe typeK pg. 54

enable/disable parametersO pg. 56

export/import calibrationExport/import pg. 53

finds device with blinking white LEDFind pg. 50


LED control

?L,11 0ASCIIDec Null

?L,01 0ASCIIDec Null

1Dec

0Null

1Dec

0Null

Short

SDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

SDA(TX) (RX)

SCLSDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

Short

SDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

SDA(TX) (RX)

SCLSDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

L,1 LED on

L,0 LED off

L,? LED state on/off?

Command syntax

default

L,1

L,0L,1

L,0

L,?

Example Response

300ms processing delay

orWait 300ms

Wait 300ms

Wait 300ms

r 0.1


Short

Short

SDA(TX) (RX)

SCL SDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

SDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

SDA(TX) (RX)

SCL SDA(TX) (RX)

SCLSDA(TX) (RX)

SCL

Find

Find LED rapidly blinks white, used to help find device

Command syntax

Find

Example Response

r 0.1

This command will disable continuous modeSend any character or command to terminate find.


1Dec

0NullWait 300ms


Taking reading

1,413ASCII

1Dec

0Null

TransmittingBlue

Standby

GreenTaking reading

SDA(TX) (RX)

SCLSDA(TX) (RX)

SCLSDA(TX) (RX)

SCL

Wait 600ms

Wait 600ms

R return 1 reading

Command syntax

R

Example Response


r 0.1


Calibration

Dry calibration must always be done first!Command syntax

Cal,dry

Cal,84

Cal,low,12880

Cal,high,80000

Cal,clear

Example Response

Cal,?

Cal,dryCal,nCal,low,nCal,high,nCal,clearCal,?

dry calibrationsingle point calibration, where n = any valuelow end calibration, where n = any valuehigh end calibration, where n = any valuedelete calibration datadevice calibrated?


1Dec

0NullWait 600ms

1Dec

0NullWait 600ms

1Dec

0NullWait 600ms

1Dec

0NullWait 600ms

1Dec

0NullWait 300ms

1Dec

1Dec

0Null

0NullWait 300ms

?CAL,0ASCII

or or 1Dec

0Null

?CAL,2ASCII

three point

?CAL,1ASCII

two point

Two point calibration:Step 1. "cal,dry"Step 2. "cal,n"Calibration complete!

Three point calibration:Step 1 "cal,dry"Step 2 "cal,low,n"Step 3 "cal,high,n"Calibration complete!


Export/import calibration

Export export calibration string from calibrated device

Import import calibration string to new device

Export,? calibration string info

Command syntax

(1 of 10)

(1 of 10)

(10 of 10)

(8 more)

(FIFO)

Export

Export

Export,?

Example Response

Export: Use this command to save calibration settingsImport: Use this command to load calibration settings to one or more devices.

Import, n

Response breakdown

# of strings to export

Export strings can be up to 12 characters long

10,# of bytes to export

120


Wait 300ms

Wait 300ms

Wait 300ms

Wait 300ms

10,120

59 6F 75 20 61 72

65 20 61 20 63 6F

*DONE

Import, 59 6F 75 20 61 72

1

1

1

1

ASCII

ASCII

ASCII

ASCII

ASCII

Dec

Dec

Dec

Dec

0Null

0Null

0Null

0Null

Export

r 0.1


Setting the probe type

K,n n = any value; floating point in ASCII

K,? probe K value?

Command syntax

K,10

K,?

Example Response

K 1.0 is the default value

K 0.1 K 1.0 K 10

1Dec

0NullWait 300ms

K,10ASCII

1Dec

0NullWait 600ms



0.3% from ideal

0.3% from ideal

0.3% from ideal

0.3% from ideal

8.82

T,19.5

8.91


T,n n = any value; floating point or int

T,? compensated temperature value?

Command syntax

r 0.2

T,19.5

RT,19.5

T,?

Example Response

1Dec

0NullWait 300ms

Wait 900ms

Wait 300ms

8.91

?T,19.5

1

1

ASCII

ASCII

Dec

Dec

0Null

0Null


RT,n set temperature compensation and take a reading*

This is a new commandfor firmware V2.13

Default temperature = 25°CTemperature is always in Celsius Temperature is not retained if power is cut



O, [parameter],[1,0] enable or disable output parameter

O,? enabled parameter?

Command syntax

1Dec

0NullWait 300ms ASCII

?,O,EC,TDS,S,SG

enable / disable total dissolved solids

if all are enabled

enable / disable conductivity

enable / disable salinity

enable / disable specific gravity

O,EC,1

O,SG,1 O,SG,0

O,EC,0/

/

/

/

O,TDS,1

O,S,1

O,TDS,0

O,S,0

Example Response

O,?

* If you disable all possible data types your readings will display “no output”.

ParametersEC conductivity

total dissolved solidssalinityspecific gravity

enableddisabled

TDSSSG

Followed by 1 or 010

1Dec

0NullWait 300ms

1Dec

0NullWait 300ms

1Dec

0NullWait 300ms

1Dec

0NullWait 300ms

Enable/disable parameters from output string


Device information

Wait 300ms

i device information

Command syntax

i

Example Response


?i,EC, 2.101ASCIIDec

0Null

Response breakdown?i,

Device

EC,Firmware

2.10

r 0.1


Reading device status

Wait 300ms

Status voltage at Vcc pin and reason for last restart

Command syntax

Status

Example Response


?Status,P,5.0381ASCIIDec

0Null

Restart codesP powered off

software resetbrown outwatchdog unknown

SB

WU

?Status,Reason for restart

P,Voltage at Vcc

5.038

Response breakdown

r 0.1


Sleep mode/low power

Do not read status byte after issuing sleep command.

Sleep enter sleep mode/low power

Command syntax

Sleep

Example Response

no response

wakes up deviceAny command

Send any character or command to awaken device.

Short

SDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

SDA(TX) (RX)

SCLSDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

Short

SDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

SDA(TX) (RX)

SCLSDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

Sleep

SleepStandby

r 0.1

STANDBY SLEEP

18.14 mA 0.7 mA

0.4 mA16.85 mA

5V

3.3V


Protocol lock

?Plock,11ASCIIDec

0Null

1Dec

0Null

1Dec

0Null

Plock,1 enable Plock

Plock,0 disable Plock

Plock,? Plock on/off?

Command syntax

Plock,1

Plock,0

Plock,?

Example Response


Wait 300ms

Wait 300ms

Wait 300ms

Locks device to I2C mode.

Short

SDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

SDA(TX) (RX)

SCLSDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

Short

SDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

SDA(TX) (RX)

SCLSDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

Short

SDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

SDA(TX) (RX)

SCLSDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

Plock,1 Baud, 9600

cannot change to UART cannot change to UART

r 0.1

default


I2C address change

Warning!

I2C,n sets I2C address and reboots into I2C mode

Command syntax

I2C,101 device reboot

Example Response


I2C,101

Short

SDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

SDA(TX) (RX)

SCLSDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

Short

SDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

SDA(TX) (RX)

SCLSDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

(reboot)

n = any number 1 – 127

r 0.2

Changing the I2C address will prevent communication between the circuit and the CPU until your CPU is updated with the new I2C address.

Default I2C address is 100 (0x64).


Factory reset

Factory enable factory reset

Command syntax

Factory device reboot

Example Response

Factory

Short

SDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

SDA(TX) (RX)

SCLSDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

Short

SDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

SDA(TX) (RX)

SCLSDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

(reboot)

I2C address will not change

Clears calibration LED onResponse codes enabled

r 0.1

Factory reset will not take the device out of I2C mode.


Change to UART mode

n =

300120024009600192003840057600115200

Baud,n switch from I2C to UART

Command syntax

Baud,9600 reboot in UART mode

Example Response

Changing to UART mode

Baud,9600 (reboot)

CPU

TX RX

BlueI2C standby

GreenTaking reading

PurpleChanging

I2C ID#

WhiteFind

RedCommand

not understood

CPU

TX RX

BlueI2C standby

GreenTaking reading

PurpleChanging

I2C ID#

WhiteFind

RedCommand

not understood

CPU

TX RX

BlueI2C standby

GreenTaking reading

PurpleChanging

I2C ID#

WhiteFind

RedCommand

not understood

r 0.1


Short

Short

SDA(TX) (RX)

SCL SDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

SDA(TX) (RX)

SCL SDA(TX) (RX)

SCL

SDA(TX) (RX)

SCL SDA(TX) (RX)

SCLSDA(TX) (RX)

SCLManual switching to UARTMake sure Plock is set to 0 Disconnect ground (power off)Disconnect TX and RXConnect TX to the right PRBConfirm RX is disconnectedConnect ground (power on)Wait for LED to change from Blue to GreenDisconnect ground (power off)Reconnect all data and power

•••••••••

Wrong Example

Example

Disconnect RX line

r 0.1


EZO TM circuit footprint

1 In your CAD software,place a 8 position header. 2 Place a 3 position header at both

top and bottom of the 8 position.

2.54mm(0.1”)

17.78mm(0.7”)

3 Delete the 8 position header. The two 3 position headers are now 17.78mm (0.7”) apart from each other.

17.78mm(0.7”)

r 0.1

3.0

1.05mm Ø


Datasheet change log

Revised Enable/disable parameters information on pages 31 & 56.

Datasheet V 4.5

Updated calibration processing delay time on pg.52.

Datasheet V 4.6

Revised cover page art.

Datasheet V 4.7

Revised definition of response codes on pg 46.

Changed "Max rate" to "Response time" on cover page.

Datasheet V 4.8

Datasheet V 5.0

Removed note from certain commands about firmware version.Added steps to calibration command pages 27 (UART) and 52 (I2C).

Datasheet V 4.9

Added more information about temperature compensation on pages 30 & 55.

Datasheet V 5.1

Revised calibration information on pages 27 & 52.

Revised isolation schematic on pg. 13

Datasheet V 5.2

Datasheet V 5.4

Datasheet V 5.3

Added new command:"RT,n" for Temperature compensation located on pages 30 (UART) & 55 (I2C).Added firmware information to Firmware update list.


Datasheet change log

Revised entire datasheet.

Datasheet V 4.0

Corrected I2C calibration delay on pg. 52.

Datasheet V 4.1

Revised Plock pages to show default value.

Datasheet V 4.2

Updated calibration info on pages 27 (UART) and 52 (I2C).

Datasheet V 4.3

Updated High point calibration info on page 11.

Datasheet V 4.4


V1.0 – Initial release (April 17, 2014)

V1.1 – (June 2, 2014)• Change specific gravity equation to return 1.0 when the uS reading is < 1000 (previously returned 0.0)• Change accuracy of specific gravity from 2 decimal places to 3 decimal places• Don’t save temperature changes to EEPROM

V1.2 – (Aug 1, 2014)• Baud rate change is now a long, purple blink

V1.5 – Baud rate change (Nov 6, 2014)• Change default baud rate to 9600

V1.6 – I2C bug (Dec 1, 2014)• Fixed I2C bug where the circuit may inappropriately respond when other I2C devices are connected.

V1.8 – Factory (April 14, 2015)• Changed “X” command to “Factory”

V1.95 – Plock (March 31, 2016)• Added protocol lock feature “Plock”

V1.96 – EEPROM (April 26, 2016)• Fixed glitch where EEPROM would get erased if the circuit lost power 900ms into startup

V2.10 – (April 12, 2017)• Added "Find" command.• Added "Export/import" command.• Modified continuous mode to be able to send readings every "n" seconds.• Default output changed from CSV string of 4 values to just conductivity; Other values must be enabled.

V2.11 – (April 28, 2017)• Fixed "Sleep"bug, where it would draw excessive current.

V2.12 – (May 9, 2017)• Fixed glitch in sleep mode, where circuit would wake up to a different I2C address.

V2.13 – (July 16, 2018)• Added “RT” command to Temperature compensation.

Firmware updates


Warranty

The debugging phase

Atlas Scientific™ Warranties the EZO™ class Conductivity circuit to be free of defect during the debugging phase of device implementation, or 30 days after receiving the EZO™class Conductivity circuit (which ever comes first).

The debugging phase as defined by Atlas Scientific™ is the time period when the EZO™

class Conductivity circuit is inserted into a bread board, or shield. If the EZO™ class Conductivity circuit is being debugged in a bread board, the bread board must be devoid of other components. If the EZO™ class Conductivity circuit is being connected to a micro-controller, the microcontroller must be running code that has been designed to drive the EZO™ class Conductivity circuit exclusively and output the EZO™ class Conductivity circuit data as a serial string.

• Soldering any part of the EZO™ class Conductivity circuit.

• Running any code, that does not exclusively drive the EZO™ class Conductivity circuit and output its data in a serial string.

• Embedding the EZO™ class Conductivity circuit into a custom made device.

• Removing any potting compound.

It is important for the embedded systems engineer to keep in mind that the following activities will void the EZO™ class Conductivity circuit warranty:

r 0.1


Reasoning behind this warranty Because Atlas Scientific™ does not sell consumer electronics; once the device has been em-bedded into a custom made system, Atlas Scientific™ cannot possibly warranty the EZO™ class Conductivity circuit, against the thousands of possible variables that may cause the EZO™ class Conductivity circuit to no longer function properly.

Atlas Scientific™ is simply stating that once the device is being used in your application, Atlas Scientific™ can no longer take responsibility for the EZO™ class Conductivity circuits continued operation. This is because that would be equivalent to Atlas Scientific™ taking responsibility over the correct operation of your entire device.

1. All Atlas Scientific™ devices have been designed to be embedded into a custom made system by you, the embedded systems engineer.

2. All Atlas Scientific™ devices have been designed to run indefinitely without failure in the field.

3. All Atlas Scientific™ devices can be soldered into place, however you do so at your own risk.

Please keep this in mind:

r 0.1


v 5.4 ezo-ec

Documents